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The Argo II is a flying Greek trireme (that could also sail if the aerial controls are damaged) built by the Hephaestus' Cabin for the journey of the seven demigods of the Prophecy of Seven to Greece. It was manned by Leo Valdez, Piper McLean, Jason Grace, Frank Zhang, Hazel LevesquePercy Jackson, and Annabeth Chase. The Argo II was destroyed when Zeus launched them to Camp Half-Blood.


Bunker 9, where the Argo II was built.

During the Demigod Civil War, Bunker 9 was used as a command post for the Hephaestus' Cabin. An unknown camper designed blueprints for a flying ship that may have been related to a prophecy, as there is a note stating "Prophecy? Unclear. Flight?" While the designer was never known, the name of the blueprints led to revealing the name of the ship—Argo II. The creator never made the ship and eventually the bunker was abandoned. Decades later, Leo Valdez had a dream about the Argo II, made out of flames, when he was two, while he was still under the care of Tía Callida. When he was five years old, he drew a picture of a flying ship with crayons. The ship was decorated with flames and its masthead was the head of the metal dragon, Festus. Leo, however, lost the drawing in the wind though it was much later returned to him by Aeolus, the master of the wind.

The Original Argo

The Argo is the original ship of Jason and the Argonauts, on which they sailed on their quest for the Golden Fleece. The ship was named after its builder, Argus. The original Jason was killed when its mast, built from a tree of the Grove of Dodona, fell on him and crushed him. The Argo II is named after the ship. 

The Heroes of Olympus

The Lost Hero

Years later, Leo discovers he is a demigod and is sent on a quest to rescue Hera, Queen of the Gods. Before they leave, Leo discovers Bunker 9 after repairing the bronze dragon that he names Festus. He sees the blueprints for the large ship he drew when he was younger, but focuses on adding a pair of wings to Festus. While visiting Aeolus to ask for help, Aeolus returns Leo's drawing of the Argo II (not named at the time) to him claiming that everything lost in the wind finds their way to him. Leo takes the picture and puts it in his pocket without showing Jason or Piper.

Leo, constructor of the Argo II.

After the quest is completed, Leo shows Bunker 9 to the rest of Cabin Nine, including the Argo II blueprints. He shows them the picture of the ship he drew when he was five, and feels that the ship is tied with his destiny and says he is going to build it, with the head of the recently destroyed Festus as the mast head. When Leo pulls out his crayon drawing, everyone compares it, and they all find that the drawing and blueprint are the same. Then, he and the Hephaestus cabin start to build it, to sail to Camp Jupiter.

The Son of Neptune

Percy has dream visions of Jason, Piper, and Leo finishing the ship and welding the head of Festus to the mast. However, the ship's samophlange breaks and Leo says it could take a few days to fix. At the end of the book, the ship appears on the horizon and Percy gathers Camp Jupiter to meet them in the Forum after he is elected Praetor.

The Mark of Athena

Festus the dragon, now a masthead

The Argo II arrives at Camp Jupiter and attracts the attention of the demigods and the legacies at camp. Terminus intercepts them by appearing on their ship, telling them that they cannot proceed past his Pomeranian Line, and that they cannot land, so they convince him to let the ship float over New Rome instead. Leo is possessed by an eidolon and fires upon Camp Jupiter with the Argo II ballista. The ship is damaged in the escape and Leo is forced to set down in Utah to collect the shield of the resurrected Narcissus in order to get the Celestial Bronze that he needs for repairs.

During their voyage across the ocean, the ship is attacked by Chrysaor, the son of Medusa and Poseidon, and his crew of Dolphin Warriors. Recalling that Dionysus was the one to transform the pirates in the first place, Percy pretends that the god is the captain of the Argo II and scares off the Dolphin Warriors. The Seven defeat Chrysaor who flees without his mask, ship, or treasure. The Seven then sacrifice all three, collected as spoils of war, to Dionysus and Bacchus.

In Rome, the Seven leave the ship to search for Nico di Angelo, only to fall into Gaea's traps. Leo devises a way for Frank to escape to the surface and contact Coach Hedge who is still onboard the ship and rescues Leo, Frank and Hazel. They then fly the ship to the Colosseum where Percy and Jason are engaged in a battle with the Gigantes Ephialtes and Otis. Coach Hedge uses the ship's weapons to blast Ephialtes, defeating him and allowing Bacchus to finish the giants off. They then bring Nico aboard where he reveals what he has discovered about the Doors of Death, including that one side is located in Tartarus.

After Bacchus departs, Leo and Frank manage to locate the Emmanuel Building where Bacchus had directed them to look for Annabeth. Coach Hedge uses the weapons to blow apart the back parking lot, exposing the shrine where Annabeth and the Athena Parthenos are located. The crew pull the statue onboard, but Arachne grabs onto Annabeth's broken ankle and begins dragging her into a pit leading into Tartarus. Unable to rescue Annabeth and unwilling to let her go, Percy orders Nico to lead the others to the mortal side of the Doors of Death before he and Annabeth fall into Tartarus.

In the aftermath, the crew, though upset sets sail for Greece to reunite with their missing friends at the House of Hades while Leo begins modifying the ship with designs taken from Archimedes' workshop including Archimedes Spheres.

The House of Hades

The ship is attacked by earth spirits with giant boulders. Leo states that it is the third time he has fixed the mast since they started getting attacked. Leo sends a celestial bronze cannon at the earth spirits and then quickly retreats. Later, when the Kerkopes come and attack, they mess up the magic walls in the mess hall and steal the Archimedes Sphere from the command console. Leo and Jason chase after the dwarfs and retrieve their stolen belongings as well as claiming Odysseus' Astrolabe and Triptolemus's Almanac for themselves.

After leaving Venice, the ship is attacked by Khione, Zethes and Calais and badly damaged while Leo is blasted to Ogygia. Piper manages to permanently activate Festus using charmspeak and Piper and Festus manage to defeat their attackers. The crew manages to dock the ship at the palace of Notus/Auster, but have very little luck in repairing it without the help of Leo. After several days, Jason is able to get Notus to lend them a team of four venti who reluctantly tow the damaged ship to Malta before Jason loses control of them and is forced to release the storm spirits half a mile from shore. Festus then manages to reactivate the Argo II's damaged engine and bring them the rest of the way in where they are reunited with Leo who is able to fix the Argo II.

Later, the Seven fly the ship to the House of Hades, but choose not to land and instead leave Coach Hedge to man the weapons. By the time the crew returns with a rescued Percy and Annabeth, Reyna has landed onboard to take the Athena Parthenos back to Camp Half-Blood. Nico, Reyna and Coach Hedge leave to transport the statue while the Argo II sets sail for Athens.

The Blood of Olympus

The Argo II falling apart after as it reaches Long Island.

The ship takes a beating throughout the final adventure to Greece. When the Argo II makes it to Greece and Percy and Annabeth are discovered by the giants and the gods come down, Leo helps in the fight by launching ballistae into the smaller monsters, but they return fire and severely damage the Argo II. When the gods arrive to help, Leo races across the deck shooting ballistae, dropping hammers on the giants heads and blowtorching their loincloths while Hephaestus works the controls, furiously working to keep the ship aloft. Although they win, by the time that the battle is over, the Argo II is left severely damaged, barely aloft and moored to the top of the Parthenon, half of the ship's oars broken off or tangled, the sails peppered with burning holes and smoke streaming from several large splits in the hull.

After the battle, to get back to Camp Half-Blood, Zeus offers to slap the ship back, but Zeus, Hephaestus and Nike all warn that the stress involved will likely destroy the Argo II and will possibly be fatal to them. However, Leo states that the Argo II can make it and that it only has to stay intact long enough for them to reach Camp Half-Blood at which point the Seven can abandon ship. Once the Seven are back onboard and strapped in with Leo's twenty-point safety harnesses, Zeus grows to a hundred feet tall, tosses the ship into the air and then spikes it to Long Island like a volleyball. Once the ship has been spiked, Jason, Piper, Frank, Hazel, Annabeth and Percy unstrap themselves while Leo struggles to right the ship as they spiral downwards in free fall. As the ship approaches the ground, all but Leo evacuate with Leo remaining at the controls and ordering the others to go, insisting that he has a plan. As Jason joins the armies of the two camps, the Argo II streaks across the sky, shedding burning chunks of mast, hull and armaments before disappearing over the western hills. However, Jason doesn't hear the Argo II explode over the sounds of battle.

After Gaea awakens, Leo suddenly returns on a rebuilt Festus. Jason realizes that Leo's secret work within the Argo II's hull over the previous few weeks had been him building a new body for Festus within the framework of the ship and guesses that Leo must've known in his gut that the Argo II would eventually fall apart.

The following day, the entire Hephaestus Cabin scours the valley for any sign of Leo or Festus but all they find is bits and pieces of the Argo II's broken hull.

Demigods & Magicians

The Staff of Serapis

When a reed boat descends from the sky to pick up Sadie Kane, Annabeth thinks for a moment that she's seeing the Argo II descending.


The ship is a magical trireme with one sail and a few banks of oars. It's 200 feet long (61 meters) with a bronze hull and a flaming dragon head at the top of the mast. The mast head is Festus' head reused. The ship's main weapons are two repeating crossbows that can fire explosive bolts powerful enough to blast through concrete. It has oars that can change into spears if needed and the mast head is able to breath fire. It is unknown exactly how the ship is able to fly, but it is able to stop in mid-air and has a landing gear system so it can dock on dry land. Both Leo Valdez and Jake Mason describe it as "A spankin' hot war machine," though Jake says this as he examines the old blueprint for the ship. The oars are retractable and automated. The controls consist of a keyboard monitor, aviation controls of a leer jet, dub step soundboard, and Wii remotes and sensor which control different aspects of the ship. The ship's power comes from the engine room on the second and lowest deck, which also houses the sickbay, storage and stables.

The Argo II has cabins for each of the seven and Gleeson Hedge. Annabeth's cabin has a desk with a stack of books, a journal, a pen and a picture of her dad flying a Sopwith Camel biplane, grinning and giving the thumbs-up. Her New York Yankees cap is also hanging from a hook on the wall and a bunk. Other than that the cabin is bare, she likes to keep it clean and simple. Coach Hedge's cabin was described to have looked like a college dorm room after a hurricane. The floor is strewn with laundry, DVDs and dirty dishes scattered around the TV on the dresser.

The mess hall is styled like Camp Half-Blood, which makes Leo feel bad, knowing that Frank Zhang and Hazel Levesque had never gone to Camp Half-Blood. There are also stables for the pegasi, however they are not very useful, as pegasi like to roam around. The lounge has cupboards lined with magic cups and plates from Camp Half-Blood, which fills up with whatever food or drink you want on command. There is also a magical ice chest with canned drinks, which are perfect for picnics ashore. The chairs have cushy recliners with thousand-finger massage, built-in headphones and sword and drink holders. There are no windows, but the walls were enchanted to show real-time footage from Camp Half-Blood- the beach, the forest, the strawberry fields. The large mess hall/lounge is located at the stern.



  • The Argo II runs on a combination of twelve ingredients mixed in an exact ratio: water from the River Styx, Lemnos Fire from the forges of Hephaestus, essence of venti, and a combination of nine other unknown ingredients.
  • Each of the seven demigods refer to the Argo II as their home throughout The Mark of Athena and The House of Hades.
  • Leo cares very much for the ship, to the point that Frank Zhang accuses him of caring more about what happens to the Argo II than about their friends. But Leo denies this, thinking that he only cares so much about it because it would ensure the safety of themselves and their friends.
  • Incidentally, Jason Grace's namesake - the original Jason - was aboard the first Argo and even led the Argonauts' quest. In addition, Frank Zhang's ancestor Periclymenus was one of the original Argonauts.
  • As seen in The Mark of Athena, due to his powers as the son of Poseidon, Percy Jackson is able to take at least partial control of the Argo II and direct the ship's movements, helping Annabeth get the ship ready to sail, although she fired the engine and actually piloted it.


The Heroes of Olympus
Core Series: The Lost Hero | The Son of Neptune | The Mark of Athena | The House of Hades | The Blood of Olympus
Main Characters: Jason Grace | Piper McLean | Leo Valdez | Percy Jackson | Frank Zhang | Hazel Levesque | Annabeth Chase | Reyna Ramírez-Arellano | Nico di Angelo | Gleeson Hedge
Secondary Characters: Hylla Ramírez-Arellano | Dakota | Tyson | Ella | Octavian | Halcyon Green | Dr. Howard Claymore | Alabaster C. Torrington | Lamia | Iapetus/Bob
Minor Characters: Rachel Elizabeth Dare | Grover Underwood | Thalia Grace | Fleecy | Mrs. O'Leary | Kinzie | Arion | Calypso | Lou Ellen Blackstone | Chiron | Will Solace | Tristan McLean | Don | Julia | Jacob | Michael Varus | Burly Black | Medea | Midas | Lityerses | Phineas | Otrera | Echo | Narcissus | Sciron | Pasiphaë
Olympian Gods: Zeus | Hera | Poseidon | Hades | Ares | Demeter | Athena | Apollo | Artemis | Hephaestus | Aphrodite | Hermes | Dionysus
Minor Gods: Achelous | Aeolus | Asclepius | Boreas | Eurus | Hecate | Iris | Hypnos | Keto | Khione | Kymopoleia | Mithras | Nemesis | Nike | Notus | Phorcys | Serapis | Thanatos | Triptolemus | Zephyros
Roman Gods: Jupiter | Juno | Neptune | Pluto | Mars | Minerva | Ceres | Lupa | Bellona | Fortuna | Janus | Terminus | Vulcan | Mercury | Apollo (Roman) | Diana | Venus | Bacchus | Pomona | Aquilon | Hercules | Cupid | Auster | Favonius | Letus | Victoria
Giants: Enceladus | Porphyrion | Alcyoneus | Polybotes | Ephialtes | Otis | Damasen | Clytius | Mimas | Orion | Hippolytos | Thoon | Periboia
Undead: Gray | Zombie
Primordial Gods: Gaea | Tartarus | Ourae | Nyx | Chaos | Ouranos | Akhlys | Hemera | Elpis | Spes
Monsters and Magical Creatures: Cynocephali | Gorgon | Gryphon | Harpy | Basilisk | Lycanthrope | Gegeines | Cyclops | Katobleps | Unicorn | Giant Eagle | Ichthyocentaur | Satyr/Faun | Storm Spirit | Laistrygonian Giant | Lares
Related Content: Rick Riordan | Haley Riordan | Percy Jackson and the Olympians | Percy Jackson and the Olympians: The Ultimate Guide | The Demigod Files | The Demigod Diaries | The Son of Sobek | The Singer of Apollo | The Staff of Serapis | Percy Jackson's Greek Gods | Percy Jackson's Greek Heroes | The Crown of Ptolemy | Demigods & Magicians | Demigods of Olympus | Percy Jackson Demigod Collection
Personal Weapons: Riptide | Annabeth's Knife | Backbiter | Frank's Spear | Hazel's Spatha | Katoptris | Nico's Sword | Thalia's Spear | Aegis | Hades' Sword | Kronos' Scythe | Ivlivs | Master Bolt | Poseidon's Trident | Reyna's Spear | Silver Bow | Hades' Staff | Juno's Gladius | Annabeth's Sword | Sumarbrander | Gungnir | Gjallar | Mjolnir | Thor's Staff | Khopesh | Mallory's Serrated Knives | Meg's Twin Imperial Gold siccae blades | Caduceus | Apollo's Golden Bow | Artemis' Knives | Ares' Sword | Ares' Shield | Thyrsus | Hecate's Torches | Minotaur's Axe | Leroy's Sword | Tyson's Javelin | Alex's Garrote Wire | Piper's Sword
Magical Items: Annabeth's Yankees Cap | Helm of Darkness | Keys of Hades | Flying Chariot | Golden Apple | Apples of Immortality | Greek Fire | Hermes' Multivitamins | Leo's Magical Toolbelt | Nectar and Ambrosia | Pandora's Pithos | Winged Shoes | Golden Fleece | Stygian Ice Whistle | Serapis' Staff | Magic 8 Ball | Arrow of Dodona | Pig Ball | Mechanical Spider | Angel Statues | Athena Parthenos | Chiron's Wheelchair | Diocletian's Scepter | Flaming Dodgeball | Gleipnir | Poseidon's Pearls | Queen Hippolyta's Belt | Mistletoe Arrow | Frank's Stick | Expand-o-Duck | Caligula's Caligae | Ran’s Net | Rune Stones | Nábrók
Spoils of War: Minotaur's Horn | Medusa's Head | Kampê's Scimitars | Nemean Lion's Pelt | Gorgon Blood | Cornucopia | Lydian Drakon Hide | Phineas' Robe and Slippers | Triptolemus's Almanac | Odysseus' Astrolabe
Items: Camp Necklace | Chameleon Armor | Daedalus' Laptop | Golden drachma | Denarius | Red Gold | Mark of Athena | Thalia's Shield | Video Shield | Wristwatch Shield | Golden Mango | Sibylline Books | Letter of Recommendation
Ships Amos' Boat | Argo II | CSS Birmingham | Egyptian Queen | Julia Drusilla Yachts | Pax | Queen Anne's Revenge | Reed Boat | Naglfar
Blessed Metals: Adamantine | Celestial Bronze | Imperial Gold | Stygian Iron | Bone Steel